During the past year we have continued our work applying rapid MRI to guide simple and complex mechanical and biological interventions. We continue to employ MRI catheterization as standard clinical practice at the NIH clinical center, based on our earlier careful pilot research comparison of conventional X-ray and wholly MRI guided transfemoral pulmonary artery catheterization in adults. We continue to enhance the capabilities of MRI catheterization to characterize heart function in patients. We have taught two dozen medical centers across North America and Europe how to adopt these techniques by hosting hands-on workshops in our labs at NIH. We have begun investigational MRI catheterization in children with congenital heart disease, to avoid radiation that can cause long term complications. So far we have performed the procedure in almost 50 patients at our collaborative facility at Childrens National Medical Center in Washington DC. We are developing new approaches to connect different heart chambers without surgery in patients with congenital heart disease. We also continue work towards direct repair of congenital heart defects on small children who otherwise might require open surgical access. We continue a strategic project to connect the great veins to the pulmonary arteries (also known as cavopulmonary shunts, Glenn shunts, Fontan shunts) in animals, and expect to be able to translate this into the care of children in upcoming years. We have developed custom medical devices to make this happen We have developed special biopsy catheters to enable a new approach to take samples of heart muscle directed by pathology identified under MRI, rather than the conventional blind approach. We showed MRI guided biopsy to be more effective than X-ray biopsy in an animal model. We have developed a completely new approach to treat heart rhythm disorders by injecting small amounts of acetic acid (vinegar) rather than conventional electrical burning (radiofrequency ablation). This new chemoablation approach provides targeted irreversible destruction of small amounts of electrical tissue in a way far more promising than conventional techniques. We are working on more sophisticated catheters for testing on patients. We are developing new low-energy MRI techniques that may allow us to use standard long conductive guidewires during catheterization without causing them to heat, and without modification. Overall we have successfully developed novel applications of real-time MRI for cardiovascular treatments, and we continue to work to clinical applications of these exciting new developments.